Graphics processing devices may be implemented to carry out a variety of image processing or other general purpose processing applications. For example, a graphics processing unit (GPU, sometimes referred to as a general purpose graphics processing unit (GPGPU), may execute applications that benefit from a high degree of parallelism, such as color correction algorithms, face detection algorithms, pattern recognition algorithms, augmented reality applications, a variety of algorithm applications (e.g., wavelet transforms, Fourier transforms, and the like), or a variety of other applications.
In general, GPUs are designed to process a series of instructions, which may be referred to as shader instructions, using one or more shader processors residing in the GPU. In an example image processing application, shader instructions may define one or more mathematical operations to be performed by the shader processors on the pixels that make up the image. By applying a shader instruction to a pixel, the pixel value is changed or evaluated according to the mathematical operation defined by the shader instruction.
Shader instructions may be organized into shader program code known as a kernel. A kernel may define a function or task that is performed by the GPU. In order to execute a kernel, the program code is divided into work items (e.g., a basic unit of work in a GPU), which are organized into one or more workgroups (e.g., a set of work items).